Condenser



C. R. FOUTZ July 2, 1963 CONDENSER Filed Jan. 6. 1961 INVENTOR. CLINTONROOT FOUTZ ATTORNEY 3,695,923 CONDENSER Clinton Root Foutz, 240Brightwaters Blvd, St. Petershurg, Fla. Filed Jan. 6, 1961, Ser. No.81,135 2 Qiaims. (Cl. 165164) This invention relates generally tocondensers, and more particularly to a condenser which takes advantageof the cohesive and adhesive characteristics of water to provide forefficient operation.

The object of this invention is to increase the rate of heat flow out ofaqueous vapor and into metal by controlling the formation of thecondensate into liquid drops before the condensed liquid can spread overthe metal surface, thereby forming a film of definite thickness and lowthermal conductivity which creates a high resistance to the higher rateof heat flow from the metal surface which is directly proportional toits thickness.

The foregoing object and others ancillary thereto are accomplishedaccording to a preferred embodiment of the invention, wherein the metalsurface condensing shape is that of inverted circular cones extrudedfrom or attached to a flat metal horizontal plate. As the condensingvapor wets this cone, the liquid will form around and over this conicalarea. This area being greater than its surface base area will energizethe surface tension and cohesive force faster than ever beforecontinuously accomplished.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of a specificembodiment when read in connection with the accompanying drawings,wherein like reference characters indicate like parts throughout theseveral figures and in which:

FIG. 1 is a vertical longitudinal section through the condensercomprising the present invention, and

FIG. 2 is a vertical transverse section through the condenser.

Referring now more specifically to the drawings, C designates theinclined condenser comprising the present invention, having a vaporinlet at one end and a condensate outlet 12 at the other end thereof.Note that outlet 12 is disposed at the lowest point in the condenser toprovide for proper drainage of liquid.

The floor 14 of the condenser is inclined with respect to the horizontaland between floor 14, plate 16, and the side walls, a condensing chamber18 is formed which communicates with inlet 10 and outlet 12.

A plurality of inverted cones or stalactite like metal members 20 dependfrom plate 16, project into condensing chamber 18, and provide surfacesupon which the vapor may impinge.

On the upper surface of plate 16 longitudinally extending fins 21 areprovided. A top plate 23 encloses a chamber 22 through which the coolingmedium may flow. An air inlet 24 in communication with chamber 22directs air through the chamber between fins 21 and out through anoutlet 26.

In operation, aqueous vapor enters the condenser through inlet 10 theentire metal surface of which is disposed at an angle with thehorizontal. The cones are 90 and the flat plate 16 at 10 to 30. Becauseof this all the condensate formed, wetting the metal surface, is undergravitational force downward. As the liquid forms, and under itsadhesive force spreads and wets the metal surface, it is apparent theWetting must cover and surround each individual cone consequentlycircularly and downwardly since that is the lateral area of the conessurface.

3,095,923 Patented July 2, 1963 Thus, the adhesive force being downwardin the direct line of the acting gravitational force increases the rateof liquid flow whereby decreasing the film thickness covering the coneslateral area. This thinning of the liquid film increases the cooling ofthe condensate film so rapidly that the surface tension quickly becomesstrong enough to form spheres on the colder decreasing lateral surfaceand disengages as rain drops of water, many before flowing down to thecones tip where all must disengage as the area for adhesion becomesnearly zero.

By creating spherical formation, the condensing vapor is prevented fromblanketing over and wetting the metal to increase surface resistance,thus preventing film formation of a thickness approximating one-fourththe drops diameter. Water vapor consists of atoms of hydrogen plus atomsof oxygen. In the vapor state, there is no cohesion between these twogases. Even in the form of saturated fog, these atoms are only pushedtogether.

However, aqueous vapor, no matter how small its contact surface is, oncontact with a cold surface, changes to a liquid at the point of contactand at that moment an afiinity is created for each other that causescohesion between the molecules which is 73 dynes at 32 The rate ofincrease of this cohesive force causing the surface tension depends onlyon the rate of temperature decrease in the liquid or condensate.

When the liquid spec is formed, this particle p0- sesses adhesion, if itwets the surface, and will spread, and its area in liquid film form as,at the contact speck, the adhesion is greatest, there being then nocohesion. By making the temperature drop sufficiently, very quickly, thecohesive force becomes greater than the adhesive force and exerts itselfwithin the liquid to form a sphere. This slow increase in surfacetension at the initial period of contact tends to determine the area ofthe condensate film or drop.

When the rate of cooling is fast enough and the temperature dropssufiiciently to generally ease the surface tension enough, the liquidwill be contracted into spherical form or liquid drop. In the adhesivestage, the form of the wetting metal can be controlled by its shape anddesign to assist the surface tension in forming as well as quicken itsaggregation.

The aqueous vapor, as fast as liquefied, will, because of its adhesiveproperty, film-form in all directions following the metal plate of tubesurface. At the moment of condensation, temperature cohesion andadhesion exist, but surface tension does not and cannot exist until theliquid temperature lowers sufiiciently. But the surface tension doesincrease in force with the rapidity of cooling, and when time isdecreased to instantaneous, adhesion ceases to be a factor. Therefore,by means that lowers quickly the temperature of the condensate, theforce of tension can be increased and drops form continuously and veryquickly. Also, by proper design, the metal cooling or wetting surfacecan be so shaped that the adhesive force causes the liquid film tospread over the metal as shaped.

Surface tension, in effect, is a contracting circular force causingspherical drop formation when its intensity becomes greater than itsexternal adhesive force. Therefore, in the old method offilm-surfaceaspread condensation, because of no cohesion in thecondensed liquid and its obstinate adherence, the film thickness becomesso great that the heat-flow from the high conductivity of the metalwetted metal surface is slowed to the low conductivity of water at itscondensation temperature and pressure.

Thus, when condensing of aqueous vapor (steam) is slowed to theconductivity of water the temperature of the condensate and the rate tothat of the water coeflicient,

then surface tension develops so slowly that the film flow remainsunbroken except when its density increases and is disrupted bygravitational force. In this device, making use of the controlled orforced film shape the liquid must take, it will be seen that thefollowing things are accompli'shed:

First, the high conductivity metal surface which. the aqueous vapor mustcontact is greatly increased.

Second, because of the greater metal surface area attained on the vaporside, the eflective mean thickness of the plate of the metal can bereduced, guaranteeing a faster heat transfer rate from the metal surfaceinto the aqueous vapor during its re-change of state to liquid andthereafter. 1

Third, by the adhesive force movement of the liquid on the metal, it canonly be circular in flow and in perpendicular direction on the cones,and the depth or thickness of the condensed film is limited by thegravitational pull as its density increases and because of its weightand adhesion, causes the liquid-to flow down the wetted face of thecones smooth surface.

Fourth, because the cones wetted face area is greater than its base, therate of cooling becomes greater than that possible from a flat or curvedtube surface. Because of this high cooling rate, the surface tension inthe liquid is formed first, and quickly increases in force, thuscreatinga hollow liquid sphere Which'flows down to the cones tip where itsadhesive force is less than the pull of gravity.

It is possible to use atmospheric air as the cooling medium in contactwith the condensers outside or cooling surface. This is true forseveralreasons:

(1) Dry air is without adhesion to metal, therefore, dry air does notwetthe metal wall, therefore,

(2) High velocity air flow with turbulence becomes very effective indissipating the heat from the heated wall,

(3) And by this structure, the eifective air cooling surface isincreased from the flat plate area.

(4) The cooling side, when raw water is to be used as coolant, must besmooth for streamline flow. When air 'is the cooling fluid, then themetal face may be slightly rough to attain turbulent air flow. Thedesign of this condenser and its control of the condensate form takesinto consideration the fluid to be-used as the cooling medium. Themetals used in its structure, conductivity, design, thickness, shape andother dimen sions such as diameter and length of cones are influenced bythe type of coolant used.

That is to say, the condenser may be cooled by salt water, river water,spring water or gases such as air under force or thermal flow, buteachhas different requirements which may dictate the use of difierentmetals.

The condenser particularly illustrated and described is for .theuse ofambient air for two very important reasons:

(a) The elimination of chemical reaction between it and the air-face.

(b) Elimination of soluble gases and soluble chemicals and deposition ofsuspended dirt.

. Using air as the heat extracting medium, pure metals can be used withtheir high conductivity instead of alloys with their low conductivity.For example, for chromium alloys, K: 19.3 to 13.8, whereas with wroughtiron, 14:36, and copper (pure), K=216. Because of this, it is possible.to make the stalagtite cones very small with copper as the conductionmaterial, as surface tension increases quicker and thus the condensatedrops are formed more rapidly.

We can now show that although K for water is higher than K,, for air,because of its great adhesive force and film thickness, the rapid heatflow outward into the coolant from the metal is reduced by the: liquidcoolant film thickness, rough surface, and the turbulent flow and scaleof mud-added resistances.

However, it is to be noted that the laminar air flow over the coolingmetal face does not adhere to or air-wet the metal and therefore,without adhesive force, its heat removal rate from the metal isincreased by a flow velocity causing violent turblence in the airstream.

Because of this and the absence of pitting scale and oxides, where theambient air is free of acid, the heat transfer from the metal exteriorcooling face into the air will be relatively rapid. When using air asthe coolant and when drops from three to five millimeters in diameterare desired, the cone dimensions will be altitude and diameter. The conedimensions affect the surface tension and heat content, and the greaterthe surface tension, the less the cone length.

Although a certain specific embodiment of the invention has beendescribed, it is obvious that many modifications thereof are possible.The invention, therefore, is not to be restricted except insofar as isnecessitated by the prior art and by the spirit of the appended claims.

What is claimed and desired to be secured by Letters Patent is:

l. A condenser comprising an elongated hollow body formed bysubstantially parallel upper and lower walls and parallel end wallscompletely enclosing the space within the body, a heat conductingpartition Wall intermediate said upper and lower walls and substantiallyparallel thereto dividing the space within the body into an uppercoolant chamber and a lower vapor chamber, said upper,

lower and partition walls being inclined to the horizontal,

integrally protruding downwardly therefrom, said cones having axesdisposed substantially vertically and being adapted to quickly coolvapor and form spherical condensate droplets which will flow by gravityto and off the cone apices, and a plurality of longitudinally extendingfins along the upper surface of said partition wall extending upwardlyinto said coolant chamber for substantially the full length thereof forconducting heat to a coolant fluid insaid coolant chamber.

2. A condenser according to claim 1 wherein said vapor and coolantchambers are parallel and have longitudinal axes disposed at an anglefrom 10 to 30 degrees with the horizontal.

References Cited in the file of this patent UNITED STATES PATENTS1,479,567 Homing Jan. 1, 1924 1,561,898 Antisell Nov. 17, 1925 1,964,890Neeson July 3, 1934 2,197,243 Moran Apr. 16, 1940

1. A CONDENSER COMPRISING AN ELONGATED HOLLOW BODY FORMED BYSUBSTANTIALLY PARALLEL UPPER AND LOWER WALLS AND PARALLEL END WALLSCOMPLETELY ENCLOSING THE SPACE WITHIN THE BODY, A HEAT CONDUCTINGPARTITION WALL INTERMEDIATE SAID UPPER AND LOWER WALL AND SUBSTANTIALLYPARALLEL THERETO DIVIDING THE SPACE WITHIN THE BODY INTO AN UPPERCOOLANT CHAMBER AND A LOWER VAPOR CHAMBER, SAID UPPER LOWER ANDPARTITION WALLS BEING INCLINED TO THE HORIZONTAL, A VAPOR INLET AT THELOWER END OF THE VAPOR CHAMA CONDENSATE OUTLET AT THE LOWER END OF THEVAPOR CHAMBER, A COOLANT INLET TO SAID COOLANT CHAMBER AT THE SAME ENDOF THE CONDENSER AS THE CONDENSER OUTLET AND A COOLANT OUTLET TO SAIDCOOLANT CHAMBER AT THE OTHER END OF THE CONDENSER, THE WALLS OF SAIDBODY BEING IMPERFORATE EXCEPT FOR SAID INLETS AND OUTLETS, THE LOWERSURFACE OF SAID PARTITION WALL HAVING A PLURALITY OF INVERTED CONESINTEGRALLY PROTRUDING DOWNWARDLY THEREFORM, SAID CONES HAVING AXESDISPOSED SUBSTANTIALLY VERTICALLY AND BEING ADAPTED TO QUICKLY COOLVAPOR AND FORM SHPERICAL CONDENSATE DROPLETS WHICH WILL FLOW BY GRAVITYTO AND OFF THE CONE APICES, AND A PLURALITY OF LONGITUDINALLY EXTENDINGFINS ALONG THE UPPER SURFACE OF SAID PARTITION WALL EXTENDING UPWARDLYINTO SAID COOLANT CHAMBER FOR SUBSTANTIALLY THE FULL LENGTH THEREOF FORCONDUCTING HEAT TO A COOLANT FLUID IN SAID COOLANT CHAMBER.